![• allows specifying a command along with the parameters
• Syntax, ENTRYPOINT application "arg, arg1".
• Example , ENTRYPOINT echo "Hello, $name".
ENTRYPOINT
• ADD command helps in copying data into a Docker image
• Syntax , ADD /[source]/[destination]
• Example , ADD /root_folder/test_folder
ADD
• ENV provides default values for variables that can be accessed within the container
• Syntax , ENV key value
• Example , ENV value_1
ENV
• MAINTAINER declares the author field of the images
• Syntax , MAINTAINER [name]
• Example , MAINTAINER author_name
MAINTAINER](https://image.slidesharecdn.com/week-6-7-241223100433-572bcf6d/85/Computer-science-docker-file-Week-6-to7-2-320.jpg)
![Build a Docker Image with Dockerfile
➢ Create a directory where the dockerfile will be stored.
▪ mkdir c1 && cd c1
➢ Create dockerfile
▪ sudo vi dockerfile
####Contents of Dockerfile####
FROM ubuntu:22.04
MAINTAINER Virtual_University_of_Pakistan
ENV DEBIAN_FRONTEND noninteractive
RUN apt-get update && apt-get install -y ubuntu-server
EXPOSE 2022
#expose the port 2022
CMD ["echo", "Welcome to it601p"]
#above command will print the message and container will exit.
#To keep it running run bash and keep it running
CMD [“PROGRAM_TO_RUN”]](https://image.slidesharecdn.com/week-6-7-241223100433-572bcf6d/85/Computer-science-docker-file-Week-6-to7-4-320.jpg)
Computer science docker file Week -6 to7
- 1. Docker file ➢ Docker Image: A Docker Image is a read-only file with a bunch of instructions. When these instructions are executed, it creates a Docker container. ➢ Dockerfile: Dockerfile is a simple text file that consists of instructions to build Docker images. ➢ Syntax # comments command argument argument1... ➢ Docker Commands for Creating a Dockerfile CMD - Specifies what command to run within the container FROM - Creates a layer from the ubuntu:18.04 FROM ubuntu:18.04 PULL - Adds files from your Docker repository PULL. /file RUN - Builds your container RUN make /file CMD python /file/file.py
- 2. • allows specifying a command along with the parameters • Syntax, ENTRYPOINT application "arg, arg1". • Example , ENTRYPOINT echo "Hello, $name". ENTRYPOINT • ADD command helps in copying data into a Docker image • Syntax , ADD /[source]/[destination] • Example , ADD /root_folder/test_folder ADD • ENV provides default values for variables that can be accessed within the container • Syntax , ENV key value • Example , ENV value_1 ENV • MAINTAINER declares the author field of the images • Syntax , MAINTAINER [name] • Example , MAINTAINER author_name MAINTAINER
- 3. Docker Commands network Manage networks volume Manage volumes Name Description attach Attach local standard input, output, and error streams to a running container build Build an image from a Dockerfile commit Create a new image from a container’s changes config Manage Swarm configs container Manage containers cp Copy files/folders between a container and the local filesystem create Create a new container exec Execute a command in a running container export Export a container’s filesystem as a tar archive image Manage images images List images inspect Return low-level information on Docker objects kill Kill one or more running containers load Load an image from a tar archive or STDIN port List port mappings or a specific mapping for the container ps List containers rename Rename a container restart Restart one or more containers rm Remove one or more containers rmi Remove one or more images run Create and run a new container from an image save Save one or more images to a tar archive (streamed to STDOUT by default) stats Display a live stream of container(s) resource usage statistics stop Stop one or more running containers top Display the running processes of a container
- 4. Build a Docker Image with Dockerfile ➢ Create a directory where the dockerfile will be stored. ▪ mkdir c1 && cd c1 ➢ Create dockerfile ▪ sudo vi dockerfile ####Contents of Dockerfile#### FROM ubuntu:22.04 MAINTAINER Virtual_University_of_Pakistan ENV DEBIAN_FRONTEND noninteractive RUN apt-get update && apt-get install -y ubuntu-server EXPOSE 2022 #expose the port 2022 CMD ["echo", "Welcome to it601p"] #above command will print the message and container will exit. #To keep it running run bash and keep it running CMD [“PROGRAM_TO_RUN”]
- 5. Build a Docker Image with Dockerfile ➢ Build the image using above docker file ▪ docker build --help ▪ docker build <options> Option Description --build-arg Set build-time variables --cache-from Images to consider as cache sources --cgroup-parent Optional parent cgroup for the container --compress Compress the build context using gzip --cpu-period Limit CPU CFS (Completely Fair Scheduler) period --cpu-quota Limit the CPU CFS (Completely Fair Scheduler) quota --cpu-shares , -c CPU shares (relative weight) --cpuset-cpus CPUs in which to allow execution (0-3, 0,1) --cpuset-mems MEMs in which to allow execution (0-3, 0,1) --disable-content-trust TRUE, Skip image verification --iidfile Write the image ID to the file --isolation Container isolation technology --memory , -m Memory limit --memory-swap Swap limit equal to memory plus swap: -1 to enable unlimited swap --no-cache Do not use cache when building the image --platform Set platform if server is multi-platform capable --pull Always attempt to pull a newer version of the image --security-opt Security options --shm-size Size of /dev/shm --squash Squash newly built layers into a single new layer --target Set the target build stage to build. --ulimit Ulimit options ➢ Some Options --file, -f : docker file name --label : set meta data for image --quite -q : suppress output --rm : Remove intermediate containers --tag, -t : set name or tag --add-host : Add custom host to IP mapping --network : set the networking mode for run commands ➢ Upon completion , it returns the image id
- 6. Build a Docker Image with Dockerfile ➢ Verify the image is crated ▪ docker images ➢ Run an image ▪ docker run name:tag <options> --workdir , -w Working directory inside the container --hostname , -h Container host name --interactive , -i Keep STDIN open even if not attached --ip IPv4 address (e.g., 172.30.100.104) --label , -l Set meta data on a container --link Add link to another container --mount Attach a filesystem mount to the container --name Assign a name to the container --network Connect a container to a network --rm Automatically remove the container when it exits --mac-address Container MAC address (e.g., 92:d0:c6:0a:29:33) --memory , -m Memory limit --volume , -v Bind mount a volume
- 7. Create a New Container Now, create a Docker container from the Docker image we created in the previous step. docker run --name it601p_m1